AstroNotes 1972 September Vol: 11 issue 07



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The Newsletter of the Ottawa Centre, RASC

Vol. 11, No. 7 - September, 1972

Tom Tothill
Mary Grey
Ted Bean

22 Delong Drive, K1J 7E6
Dom . Observatory, 994-5474
399 McLeod Street, K2P 1A5
The Ottawa Centre will be host to the 1973 General
Assembly of the Royal Astronomical Society of Canada.
Winnipeg wants it in '74 to go with their Centennial, and
it's about our turn anyway.
Naturally, these affairs are not organized without a
considerable team effort, and we already have a considerable
team under the chairmanship of Malcolm Thomson, about to
hold its second meeting. The first departure from tradition
will be that it is not to be held on the Victoria Day week-
end, but the weekend after, namely May 25-26-27. Carleton
University happens to be in use over the holiday weekend.
(Would other news-letters kindly mention this for the
benefit of those who plan far ahead?)
The 'Gassy' Committee is most anxious to receive ideas
as to how this can be the best General Assembly ever, and
there is no time like the present to think and put forward
your ideas. There are thoughts, for example, that some
members might be willing to accommodate a student or two in
their homes, which might make quite a difference in the
number who decide to come, especially from the more distant
Centres, We hope that visitors will be able to decide their
own options as to tours, etc, rather than have to take an
all-or-nothing package deal. The fact that we will miss the
travel rush of the holiday weekend nay actually be a favour­
able factor, and it does not seem impossible that some
families might even come in campers and explore the National
Capital at their leisure after the Assembly.
We hardly expect to be able to out-do the Westerners in
the marvellous hospitality they have shown in recent 'Gassy'
— but we're sure going to try!
Mr. Hans Klinkenberg has gone to Laval U . to teach, so
Dr. Tom Legg becomes our third President this year!OBSERVERS GROUP MEETING
Cathy Hall
Our last meeting before the advent of the warm, clear
(?) summer months was held on June 2nd.
Mr. Tothill, our illustrious chairman, gave a brief
account of the activities of Rick Salmon, one of our ori­
ginal meteor observers, who is now doing astronomical work
down in Chile. Apart from the strange and wonderful skies
of the southern hemisphere, he has the fortune to see the
green flash almost regularly!
In the absence of Walter Turner, Rolf Meier talked on a
new 7" mask that can be used to "stop down" our 16" scope.
He also mentioned the occultation of an 8.9 mag star by Ju­
piter on June 18th.
John Conville told a tale of the perils of ...polyester
resin (!), with reference to its possible uses in making
bearings, scope tubes, eye piece holders, and other assorted
Slides were presented courtesy of the Tothill-Lossing
duo, followed by a very down-to-earth discussion of the pro­
gram "Chariots of the Gods", initiated by Karl Poirier,
More slides, these of the solar eclipse (not this year!)
were shown by Dr. Lossing, with mention of shadow band ex­
periments, planets visible in totality, and exposure time for
the various features.
In closing, a film was shown on a macro-to-micro view of
the universe - from galaxy to atom, courtesy Mary Grey,
* * * * * * * * * * * * *
Robert Dick
This summer I had the privilege of accompanying the
'Star Truck' on its 10,000 mile voyage beyond the skies of
Ottawa. The trip took us to Vancouver and then, in a round
about way to Kitt Peak National Observatory via Mount Hamil­
ton (Lick Obs.), Mount Wilson and Mount Palomar Observatories
At Kitt Peak, we were the farthest south of the trip
giving us a grand view of the more southerly constellations
of Sagittarius, Scorpio, Centaurus, and others. AlthoughSagittarious and Scorpio are not new to our latitude of 45°
they are partially obscured by base and tree lines. At Kitt
Peak (lat. 32°) they are well up in the sky, with Scorpio
shyly revealing its entire curving hooked tail.
The jewel of the sky was viewed for the first tine by
all our party, Omega Centaurus (NGC 5139). This globular
cluster was too far south to be seen by Charles Messier but
for those in lower latitudes it nay be seen naked eye.
It is 3 /4° in diameter as seen by m y 10 x 50 binos.
Being well away from the interstellar clouds of gas of the
Milky May it was very conspicuous. Twinkling by resolved
stars against a silver background of stars too din to be
seen, it was worthy of its fame. In Allen's 10" f/4.4 re­
flector it was over-exposed, filling the field of view at
about 200x.
Scorpio contains over a score of objects only a few of
which are observed adequately in Ottawa. Of these lower
objects many are fine targets.
The open clusters were exceptionally bright and dense.
A prime example was NGC 6242. It contained numerous eighth
magnitude stars in the form of a closed V (declination -39°).
Globular clusters were generally conspicuous, NGC 6192
running about 9 .5. The core was very bright and extended
with little change to its edge. The dimmest object I iden­
tified was NGC 6322. It appeared as 2 stars with slight ne­
bulosity between then. It is just east of Eta Scorpio at
declination -43°.
Allen Miller photographed the constellations near the
horizon, showing the lower regions which are obscured by our
latitude. They show several D.S. objects up and away from
the horizon, an eye-opening picture for those used to the
high latitudes.
Intense observations of many of the southern objects
were hindered by cloud; observing was useless to inpossible
on almost all of the nights we were on the mountain. The
clouds decided to clear for us the last night. We were for­
tunate, causing this observer to note that "We do not just
believe in miracles; we depend on them!"THE STAR TRUCK GOES TO THE SOLAR ECLIPSE
Rolf Meier
The contents of the Star Truk when it left Ottawa were
Allen Miller, Jon Buchanan, Rolf Meier and 83 telescopes.
It ended up being a wonderful expedition into the gasping
depths of the Gaspe, which returned with pictures of the
effects of darkening on atmospheric water vapour condensation
It was also discovered that overloading a mount doesn't
amount to much.
Although it was perfecty clear upon our departure from
home, Murphy had already gotten a head start on us, for
though it was also clear at Les Mechins, we overtook some of
his rainstorms on the way.
Our camp-slte at Les Mechins was provided very kindly
by Captain Verreault, the owner of the village shipyard.
It overlooked a cliff over which we looked with care. He
also provided us with access to his swimming pool and ten­
nis court which was greatly appreciated by all.
The Morning brought distressing news as Tom Tothill
translated the weather report. It predicted that 5 minutes
before first contact, one giant cloud would develop over the
Gaspe Peninsula, rain, and then clear up just after last
contact. Everyone immediately went into a panic, and rushed
off blindly in all directions. Already the cirrus were seri­
ous. The crew of the Star Truk alone remained calm, and the
decision was reached. We were going to get out of there as
fast as we could, or we were doomed. Ken Hewitt-White, our
meteorology expert, predicted a hole in the clouds 5 degrees
in diameter far inland in Le Parc, and he had left to seek
it out. (He had determined this after measuring the next
evening's shower.)
When the Star Truk finally parked in Le Parc, our si­
tuation looked poor. The three of us could contact no one
else to establish the sky conditions where others might be
stationed. We threw our drink cans into a cool stream to
cool them off, and we relaxed for several hours, observing
the great mountain scenery. Meanwhile the cumulus clouds
were accumulating.
It was then that a critical choice had to be made. It
wars 50 / 50 , and even at that time we knew we would make the
wrong choice no matter what it would be. Left was seaward,and right was inland. Well, we were not right, and soon we
saw the coastline, where we again made a stop. Once more we
had a lengthy rest, next to a large brick building, where we
later discovered that Ken, Joan, and Dave spent the night,
After a few more hours of contemplating the haze, we decided
to pick our observing site. We looked in every direction,
and decided the best place would be in the easily inacces­
sible Gulf of St. Lawrence. The inland situation looked
hopeless. In desperation we headed along the coast, stop­
ping a few miles before Cap Chat.
All was unpacked, as the local youngsters watched with
awe. The sky was hazy, with occasional distinct shadows as
a clear spot moved in. As we watched the soon going across
the sun our excitement mounted. Perhaps we would be able to
observe totality after all! The great moment came, and the
sun went through Baily's Beads, the diamond ring, and the
sun was totally eclipsed. The cameras went crazy on Allen's
10" and my 8", and I quickly removed my camera to look at
the fantastic prominences. Five seconds later it was com­
pletely overcast. We were rewarded with 5 seconds of total­
ity. All we could see now was a very dark sky, and a pink
horizon. Along the road, the mercury-vapour lights came on,
and the drivers wisely turned their headlights on. Two
minutes later the prominences were again briefly observed,
the moon again left the sun uncovered and was observed
during a few more clear periods. The partial phases were
now totally unexciting, and we packed to rejoin the remain­
ing group at Les Mechins.
We discovered with glee that Les Mechins had been com­
pletely clouded up, which made our desertion not entirely
in vain. It was also reported that several groups that had
travelled far inland into the peninsula had observed the
eclipse completely and totally, which caused us to examine
more carefully the reasons for which we had turned left In­
stead of right, and it was concluded that Murphy had made
certain we would not have the best luck.
Murphy even had his revenge on those who saw the ecli­
pse flawlessly. Dave Paterson's Datsun was the victim as
Murphy took a ditch full of mud and doused Dave, Joan Hos-
kinson, and Ken Hewitt-White, and destroyed 'Woodstock' in
the process.
The Star Truk returned home very carefully.THE SPIES WHO GAME IN FROM THE COAST
Joan Hoskinson
The summer activities of the Observers Group have been
secretly infiltrated by two spies from the West Coast.
Reports have confirmed that the two hold their head­
quarters at the H.R. MacMillan Planetarium in Vancouver, and
are believed to be associated with the R .A.S.C.
Known only as Joan E, and D . Dodge, the pair have
apparently gathered valuable information on observational
methods in Ottawa. It has also been revealed that their
main source of information was a contact in the Observers
Group itself answering to the code name "Blewitt".
The duo did not arrive simultaneously and therefore did
not create a sizable amount of suspicion. Joan E was able
to make a preliminary examination of the Observers Group as
a whole at Les Mechins, Quebec, during the July solar eclipse,
and noted the group's reaction when faced with its old enemy:
Murphy.# However, her report includes a favourable mention
of the effort and success of a few resolute souls who left
the base camp for blue skies and the total eclipse.
Almost a month later, D. Dodge joined Joan E secretly
in Ottawa and together they discussed her findings in a
series of meetings with the informer "Blewitt". By that
time, Joan E had outlined several points at which the Ottawa
group had excelled, namely, the opportunity for every member
to become involved in any aspect of astronomy he wished, and
to any degree.
Feeling that it was time for the Vancouver Centre to
mature, Joan E and D. Dodge held a summit conference debating
at length the feasibility of an observers group there.
Finding a suitable observing site around their city proved
to be more than frustrating, and the evening ended on a note
of Southern Comfort,
(Pie-eyed spies?
The two gathered a separate report on eastern amateur
astronomers at Stellafane. The findings in that report are
as yet undisclosed, but are thought to contain an incident
whereby Joan E and an unidentified member of the Ottawa group
located M57 for a clueless prizewinner. Evidently the fields
of his finder and telescope were in slight disagreement, and
his young son had crippled the eyepiece. As the story goes,
# See next page.Joan E then suggested the addition of diodes on his tele­
scope tube, the use of a Skalnate Pleso, and the acquisition
of handcuffs for his son.
Shortly after the Stellafane weekend, D. Dodge returned
to Vancouver, leaving Joan E to do follow-up research on
meteor-observing techniques at the Quiet Site. Her report
is said to contain details of how major meteor showers are
handled at Q.S., and it is believed that the information
came from her own experience in observing the Perseids in
mid-August. Since the Quiet Site is a limited-access,
government-controlled area, it is suspected that she again
received the help of the dastardly "Blewitt”.
No one knows what the repercussions on the Ottawa
Observers Group will be when this report begins to take the
shape of an observing syndicate in Vancouver. It is thought
that once this organisation is built up into an elite breed
of superior observers, they may obtain more observational
and technical secrets through the as yet undiscovered infor­
mer, "Blewitt”, in exchange, sources say, for a private
showing at the H.R. MacMillan Planetarium.
# Since the eclipse, Joan E has made an intensive study
of the substantive "Murphy", including psychological as well
physiological data.
* * * * * * * * * * * * *
Jean Knapp
My husband Harold and I, accompanied by Barry and
Michael Matthews and Barry's friend Frank Rambeau, had an
enjoyable but uneventful trip to Les Mechins, P.Q. We left
Ottawa early Friday morning, camped overnight at Riviere du
Loup, and arrived at the appointed campsite in Les Mechins
about noon on Saturday, July 8. We had the use of this
campsite free thanks to the kindness of Tom Tothill's friend
"The Captain"; also enjoyed his pool and had real "down to
earth" facilities. The site was ideal for viewing the
eclipse, and the St. Lawrence. There were about 65 people
camping, some of them members from other Centres and the
The weather was ideal up to eclipse day and then clouds
moved in steadily until, at the time of the beginning of the
eclipse, 3:24 p.m., there were few clear patches betweenclouds. We saw the first "bite" the moon took out of the
sun, with occasional glimpses of the continuing coverage of
the sun, - then a solid mass of clouds obscured our view.
Next it got slowly dark, and darker, an eerie feeling, with
the lights of Les Mechins being turned on, the church bells
ringing, car lights on, and then very cool. It started to
get lighter after about two minutes, and then it was all
over. I was disappointed along with many others. I don't
expect to see another total eclipse in my lifetime.
We started home about 5 p.m. on July 10, camped over­
night at Rimouski, and arrived back in Ottawa about 8 p.m.
on the 11th.
We all had a nice trip into an area of Canada Harold
and I had never visited before, but we sure hope to return
some day.
* * * * * * * * * * * * *
Jean wants to resign as Solar Co-ordinator. Not because
this little bout with Murphy has got her down but because
she is going to be on shift work which may interfere quite
often with her ability to attend meetings.
She has been a most enthusiastic and cheerful Co­
ordinator and feels it has taught her a lot about the Sun,
which she has faithfully observed every sunny day, and she
fully intends to keep on reading, and observing when she
"Thanks to all for many happy and educational hours;
also for the help so willingly given to me by all," she
writes. "If any of you have occasion to be in or near
Smiths Falls, please come and see me.”
We will, Jean!
And many thanks.
For the record, The Knapps live at 12 Mary Street South,
in Smiths Falls.
* * * * * * * * * * * * *
It is a great pleasure to welcome Ted Bean back to the
land of the living after several years of health problems.
The surgery he underwent this summer appears to have been
a complete success.
-Everybody.VARIABLES (1)
Jon Buchanan
When you look up at night and see the silent twinkling
of royal splendour known as stars, it is often difficult to
grasp what they really are. It is even harder to think of
then as being anything but the constant points of light we
see in the night sky, rising and setting as the sun and noon.
Host of then are as constant and stable as they look, accor­
ding to our lifespans. But there is a snail percentage of
stars that are not what they seem to be.
These stars have attained the name of variables, a word
that describes their nature better than any other. For these
are not the untroubled nuclear gas balls most stars, and our
sun are. They are undergoing internal changes or external
upheavals causing them to oscillate, spew gas into the cold
vacuum of space, exert forces that release vast amounts of
radiation or sets them off in uncontrolled explosions that
rip them apart!
These may be young stars trying to settle down on the
main sequence, old stars that are going out with a bang, or
a whimper, or normal stars that have reached that stage in
life that causes them to act as they do,
I intend to Introduce you to this minority of stars,
which consists of slightly more than twelve thousand to date.
Along with a description of these objects I hope to be able
to show you the work that amateurs, and professionals, have
done in this area. You will read about such stars as Ceph-
eids, RR Lyrae types, long-period variables, erratic, Wolf-
Rayet, flare and T Tauri type stars, singular and recurrent
novae, a bit on pulsars, and naturally quasars and, of course
eclipsing stars.
So much for the introduction; if it hasn’t caught your
attention by now ... well, I tried. On with the reason for
this article. Most often variables are introduced in the
fora of a history of their discovery. However, I will not
do that, for who is interested in learning that David Fabri-
cius discovered the first one in 1596, the star Omicron Ceti,
that wasn't on contemporary star charts but was a conspicuous
3rd magnitude at the time? Or that it wasn’t recognized as a
variable until 40 years later by Bayer; or that no other
variable was found, except Algol the winking demon star,
until Delta Cephei in 1784?-10-
Instead I’ll start with how variable stars are named
and how they are classified. If, when a variable is found,
it doesn’t have a Greek letter to name it, a ritual is evo­
ked to name this new variable. The ritual, choosing a letter
is to take the next letter in a series that starts with R and
goes on to Z. If there are more than 9 variables in this
constellation, i.e. all the letters are used, then double
letters are used: RR, RS, to RZ, then SS, ST, to SZ contin­
uing down to ZZ. If, again, there are more than the 54
variables present, thus claiming the 54 possible names given,
double letters are again used, starting with AA, AB, to AZ,
BB, BC, to BZ, going down to QQ, QR, to QZ, with the letter
J always omitted. This gives a total of 334 for those keep­
ing score (count then yourself if you don’t believe me - I
just did!). In some constellations, like Cygnus and Sagitt­
arius, there are more than a mere 334 variables. For these
a capital V is used, followed by its number.#
After these
put to the star,
tion in which it
TX Pisc, GK Ori,
identifying letters and numbers have been
it is followed by the name of the constella­
is located. Examples of these are X Herc,
V2414 Sgr.
Some variables show tendencies towards certain types of
behaviour, which sets them apart into groups. These groups
are called after the first of their kind to be found, or in
some eases, the brightest. Though most can be labelled and
put into groups, as usual there is an almost continuous
’spectrum' which leaves some between two or more groups, and
thus the boundaries for some groups are difficult to deter­
mine. Examples of some groups, in general, are RR Lyrae
types, long period variables, T Tauri types and RV Virginis
types, to cite a few.
One way to illustrate the behaviour of variables is to
plot a light curve of their visual magnitude versus time.
Professionals, and some advanced amateurs, can do light
curves at different wavelengths of light, and also radio
wavelengths, plus spectrum variations with time! Light
curves, of any kind, are the representations of data which
have been obtained over some period of time.
For visual observation this data consists of estimates
taken a week apart for long period variables, to several
estimates a night for erratic and Flare type variables, and
# Ritual is right. What a clumsy muddle!
-Ed.seconds apart in Quasar work being done by several members.
For these light curves, periods sight be seen which, usually,
don't correspond exactly with the predicted period of the
star, if it has a predicted period. This discrepancy is at­
tributed to the fact that the predicted periods are averages
of many periods, and are thus useful as a guide only, around
which the actual observations fall. This is, of course, if
a period can be discerned. Some, like erratic stars, and
some of the Quasar work, show chaotic curves from which no
period can be determined easily. Therefore, unless you work
at it in greater depth, you pass it on to others who have
the tine and equipment to try to solve it. And some are un-
solvable even with the use of computers.
An example of a light curve, mine for X Herc , is given
below to serve as an example of one. (No derisive remarks,
Cathy Hall
While at Les Mechins for the solar eclipse of July 10,
I happened to make the acquaintance of a Mr. Jim Kloeppel,
president of the Sioux City Amateur Sky Observers, and an
exchange of ideas followed. Several of these are rather
The SCASO have a "SKYWATCH" program whereby on any
given clear night there is always someone observing.
Persons unable to obse rve on a given night are assignedanother. They have responsibility for whatever is happening
at that time - a meteor shower, occultation, aurora, lunar
eclipse, etc. The trend is towards a much more scientific
approach, This is also reflected in their restriction of
star parties and group observing sessions to active observing
members, and their requirement of a monthly report to be
submitted to the president.
For our Centre, I think a written monthly report of
some kind would be an excellent idea, forcing people (other
than just the Co-ordinators) to let others know what they've
been doing. And, at the end of the year, these reports
could also be considered in the selection of recipients of
Observer of the Year and Merit Awards. In December, how many
people can remember all that they did, say, in March?
In case of any unexpected event - suspected finding of
a comet, nova, etc, the SCASO "HOTLINE" is alerted on the
decision of the president. In our case, one would probably
alert the Co-ordinator.
For beginning observers, there is a "beginner's pack­
age". This, I think, would also be an excellent idea for our
group. We have all sorts of hand-out sheets - why not col­
lect them into a package for new members? This could include
several sheets prepared by each of the Co-ordinators, with
suggestions as to activities in that field. Charts and
diagrams should be included as well - such as a general
instruction sheet for meteor observing (which has 4 sky
maps), several variable star charts, examples of drawings of
astronomical objects, a list of M objects to look for, etc.
This package would hopefully encourage the new member
to get involved, and give him ideas as to what he can do.
* * * * * * * * * * * * *
There was an old lady from Blight
Who travelled far faster than light.
She went out one day
In a relative way
And came home the previous night.
-Hu Dunnett?
Rolf Meier
It is vital that there is no movement of the image
while the exposure is being made. Accounting for the move­
ment caused by the rotation of the earth will be the clock
drive. It should track very steadily, with no unpredictable
jerking, and it should have good accuracy. This is usually
no problem with exposures of less than a second, but a
superior drive may be needed for anything longer. Getting
a good drive is not really such a great problem, however,
and as long as the RA axis is smooth, it is the only unit
that has to be in good working order.
The most difficult source of image movement to correct
is vibration, because every part of the telescope, mounting,
and camera adapter is involved. Unless the mechanical parts
of the telescope are extremely solid, vibration will be
induced by the wind, nearby persons, local earth tremors,
and even the snap of the shutter. Almost every telescope
is susceptible in some degree, and usually it is enough to
be annoying. The really sneaky cause of vibration is the
camera shutter, and if the camera is a reflex, the problem
is increased by the heavier mirror, which flips as the ex­
posure is made. Not only that, but the vibration may be so
small and short as to be unnoticeable once the exposure is
over and the mirror has returned, and yet may be at a maxi­
mum when the shutter is open.
A good mounting will not be affected by an ordinary
breeze, but even so a windscreen should be set up to avoid
the disappointment that will be caused by a sudden gust.
Needless to say, even a steady wind will be a problem on
some mounts, and they should not be used at
The best windscreen is an observatory with a slit, but
this is beyond the reach of many. Portable mountings can
be set up in the shelter of a hedge or similar barrier.
Making the windscreen portable is more clumsy, since it will
usually consist of plywood sheets, which may be difficult
to support. In the winter the problem is simplified, be­
cause merely by shovelling an average Ottawa snowstorm away
from around the scope a fairly high wall can be built up.
In time, at least, a good height can be achieved, m a k ing a
sort of half-igloo. In
addition, plywood sheets can bejust stuck into the snow.
For best results, the only person in the vicinity while
taking the pictures should be the photographer. While it
say be nice to have company (depending on whom), or someone
to take notes, they may become annoying if they suddenly
sneeze or decide to rip your diagonal out of your telescope.
It would be a good idea to see how long your telescope
vibrates after you touch it. Observe the image at high
power, and then count the number of seconds required for the
image to become steady after the telescope is tapped fairly
hard. Remember to wait at least that long and a few seconds
longer before exposing the film if you have touched the
telescope. Also cheek to see what effect walking around
will have by jumping up and down a few times.
Assuming now that all the other causes of movement have
been eliminated, the most unavoidable opening of the shutter
has yet to be dealt with. The technique of avoiding vibra­
tion will vary from camera to camera. First of all, a cable
release is all-important, the longer and more flexible the
better. That way, touching the telescope can be minimized.
The least efficient method is to use the cable release to
directly activate the shutter, which means that whatever
vibration thereby caused will be evident. In some reflex
cameras, the mirror can be independently flipped up and once
this has been done, the exposure is made when all other
vibrations have died down. If the camera has a time delay,
it should be used to expose after the movement caused by
squeezing the cable release has died down. An excellent
way to eliminate the effect of the shutter's vibration is to
make the exposure by way of another shutter not associated
with the camera and not touching any part of the telescope.
This can be nothing more than a black card held between the
film and the eyepiece, which is removed for an instant to
make the exposure. For this purpose, the camera is set on
"bulb" to open the shutter; but ensure that the card is in
place, not touching any part of the camera or telescope.
It is removed when all vibrations are certain to have died
down, and replaced when the time calculated for the exposure
is over. The only difficulty is that times less than one
second are vary difficult to judge in this way. It must be
ensured that the card is moved quickly otherwise one part of
the image will receive much more exposure than the other.
Vibration is one of the most difficult problems theamateur has to overcome, because the sources are so varied
and hard to trace. Though it may not be eliminated it can
at least be controlled and avoided at critical times.
* * * * * * * * * * * * *
Barry Matthews
Most amateurs have at one tine or another, salvaged or
used surplus eyepieces. In a number of eases this is the
most economical way to enjoy astronomy. There is nothing at
all wrong with this, and it goes to prove how ingenious the
average amateur is with his usually depleted pocketbook.
One of the most often heard complaints is: "I wonder what
power I am getting." This problem was solved for us in the
latter part of the 19th century by a very skilful amateur
astronomer, the Rev, E.L. Berthon with a device to be known
as the "Berthon Dynamometer".
By careful tracing of Fig. 1 # on drafting linen or
tracing paper one has with a little ingenuity a perfectly
adequate dynamometer at little or no cost.
1. Trace Fig. 1 on drafting linen or tracing paper.
2 . Provide a rigid frame of metal or wood (I used a
metal rectangle).
1. Insert surplus or commercial eyepiece in eyepiece
holder and put in the infinity focus position.
2 . Direct the scope at some distant scenery or the
sky (the duller the day the better). Close behind
the eyepiece you will see a small white disk. This
disk is known as the "Ramsden Disk".
3. With the dynamometer measure this disk so that its
edges just touch the two lines (see example).
Record this reading and repeat one or more times
(allowing for errors) and average the results.
4 . Calculate the magnification using the following
M = Magnification
DO = Diameter of objective
in m
DD = Diameter of the Ramsden Disk.5.
Calculate the focal length of the eyepiece using
the following:
FE = Focal length of eyepiece in mm
FO = Focal length of objective in mm .
M = signification of the system.
Fig. 1
(# by A.C. Curtis, Journal of the British Astronomical
Association, Vol. 81, No. 1, page 24)
Ramsden Disk measurement
Dia. of objective
152.0 (DD)
1200 (FO)
M = DO/DD = 58.46
Focal length of objective
FE = FO/M = 20.5
(Note: Actual eyepiece Kellner 20 mm ).
* * * * * * * * * * * * *
Is anyone carrying out lunar observations? The Lunar
Co-ordinator would like to hear of any program being carried
out (occultations, grazes, drawings, etc). I am getting
lonely. Call me or drop me a line.
Barry Matthews
133 Woodridge Cres, Apt 1, K2B 7T2REPORT FROM THE METEOR SECTION
Ken Hewitt-White
Contrary to popular belief, the meteor team is alive
and well and still observing from the 'other place'.
Actually, our greatest trials have not been kidnapping
people from N.M. but trying to stay ahead of the Mighty
Murphy and his clouds. The summer has been exceptionally
bad for any kind of observing, much less meteor observing.
Once again the Perseid shower was showered out and we were
afforded very little opportunity to study either side of the
max. either. Our best night to date has been Aug 10/11 when
we clocked 655 meteors, a rate of some 26 meteors per hour
for each person that was present.
Despite the bad circumstances this year, the team con­
tinues to receive support from the observers. We have, as
of Aug 20, clocked 2319 meteors on 29 nights. This total is
poor only when compared to the last two record-breaking
years. We are still managing to keep track of minor streams
for the American Meteor Society and if the weather ever im­
proves at all we shall be able to supply them with almost as
much information as ever.
The work this year has been conducted by 14 observers,
two of which are brand new. Rolf Meier is a new observer
and. so is Joan Hoskinson, a Vancouver Centre member no less,
who has been in Ottawa for the summer. In fact, Joan is
pretty well our best observer this year, having logged 567
meteors in 321⁄2 hours on-time.
I would like to thank Cathy Hall who acted as Co-ordin­
ator while I was away this spring. Her enthusiasm kept the
group going and has provided us with some more data on the
new June Lyrid shower, as well as our first-ever results on
an obscure radiant in Bootes, We are indebted also to Rolf
and Jon Buchanan for their very generous donation of many
reels of tape for the Q.S, tape recorder. Our running-out-
of-observing-tape nightmares appear to be over. Finally,
the co-ordinator is pleased and gratified to announce that
he was able to present an illustrated talk at the annual
Stellafane convention in Vermont concerning the activities
at the Quiet Site. It was well received.
* * * * * * * * * * * * *
The following was received by me (HW ) from the Mac-Millan Planetarium on Aug 17 prior to release to the local
(This report condensed from my copy).
An enormous planet 90 times the mass of Earth once cir­
cled our sun in an orbit between those of Mars and Jupiter.
16 million years ago that planet disintegrated, possibly in
the greatest explosion the solar system will ever experience.
Almost all traces of the planet have vanished. Only the
Asteroids remain - 1/900th of the planet's original mass.
These dramatic insights have been drawn by UBC astronomer
Michael Ovenden based on his new theory which he calls the
'principle of minimum interaction distribution'. Ovenden
has developed a new technique of calculating the changing
orbits of planets over time that allows him to verify his
theory. Bypassing the use of integrations he has been able
to get computers to play back the orbits of the planets a
thousand million years instead of just one million. The
results he has obtained verify his theory that planets even­
tually seek out orbits which minimise the mutual attractions
on each other. His calculations worked for the satellites
of Uranus and Jupiter and also for the bodies orbiting Bar­
nard's Star. However, he found his calculations would only
work on the 9 planets of the solar system when a mass 90
times that of the earth was assumed to be orbiting just out­
side of Mars 16 million years ago. Our solar system does not
follow the minimum interaction rule now because the planet
exploded 16 million years ago. For this reason, Ovenden says
the solar system is now adjusting into a new minimum inter­
action spatial distribution. He has drawn up a chart showing
how the 9 planets will change orbit over the next few million
years. Dr. Ovenden is now concentrating his time on finding
out how and why this 10th planet would explode so long ago,
and where the remaining 89 or so earth masses might be. He
calls the lost planet "Aztex" in recognition of the two sites
in Texas and Mexico where he did his research.
* * * * * * * * * * * * *
Tom Tothill
"Red, your picture finally made the Toronto Comet."
"That's nice. What page?"
"Let's see. Here it is. Thirteen."
"Isn't that the obituary page?"
"Well, er, urn, uh, duh....."
"Save me a copy."ASTRO NOTES
Miss Rosemary Freeman
College St.
Toronto 130, Ont.